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1.
Ultraschall Med ; 44(1): 56-67, 2023 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-34768305

RESUMEN

PURPOSE: To assess the longitudinal variation of the ratio of umbilical and cerebral artery pulsatility index (UCR) in late preterm fetal growth restriction (FGR). MATERIALS AND METHODS: A prospective European multicenter observational study included women with a singleton pregnancy, 32+ 0-36+ 6, at risk of FGR (estimated fetal weight [EFW] or abdominal circumference [AC] < 10th percentile, abnormal arterial Doppler or fall in AC from 20-week scan of > 40 percentile points). The primary outcome was a composite of abnormal condition at birth or major neonatal morbidity. UCR was categorized as normal (< 0.9) or abnormal (≥ 0.9). UCR was assessed by gestational age at measurement interval to delivery, and by individual linear regression coefficient in women with two or more measurements. RESULTS: 856 women had 2770 measurements; 696 (81 %) had more than one measurement (median 3 (IQR 2-4). At inclusion, 63 (7 %) a UCR ≥ 0.9. These delivered earlier and had a lower birth weight and higher incidence of adverse outcome (30 % vs. 9 %, relative risk 3.2; 95 %CI 2.1-5.0) than women with a normal UCR at inclusion. Repeated measurements after an abnormal UCR at inclusion were abnormal again in 67 % (95 %CI 55-80), but after a normal UCR the chance of finding an abnormal UCR was 6 % (95 %CI 5-7 %). The risk of composite adverse outcome was similar using the first or subsequent UCR values. CONCLUSION: An abnormal UCR is likely to be abnormal again at a later measurement, while after a normal UCR the chance of an abnormal UCR is 5-7 % when repeated weekly. Repeated measurements do not predict outcome better than the first measurement, most likely due to the most compromised fetuses being delivered after an abnormal UCR.


Asunto(s)
Retardo del Crecimiento Fetal , Nacimiento Prematuro , Embarazo , Recién Nacido , Femenino , Humanos , Estudios Prospectivos , Ultrasonografía Prenatal , Recién Nacido Pequeño para la Edad Gestacional , Ultrasonografía Doppler , Peso Fetal , Edad Gestacional , Arterias Umbilicales/diagnóstico por imagen
2.
Ultrasound Obstet Gynecol ; 56(2): 173-181, 2020 08.
Artículo en Inglés | MEDLINE | ID: mdl-32557921

RESUMEN

OBJECTIVES: To explore the association between fetal umbilical and middle cerebral artery (MCA) Doppler abnormalities and outcome in late preterm pregnancies at risk of fetal growth restriction. METHODS: This was a prospective cohort study of singleton pregnancies at risk of fetal growth restriction at 32 + 0 to 36 + 6 weeks of gestation, enrolled in 33 European centers between 2017 and 2018, in which umbilical and fetal MCA Doppler velocimetry was performed. Pregnancies were considered at risk of fetal growth restriction if they had estimated fetal weight and/or abdominal circumference (AC) < 10th percentile, abnormal arterial Doppler and/or a fall in AC growth velocity of more than 40 percentile points from the 20-week scan. Composite adverse outcome comprised both immediate adverse birth outcome and major neonatal morbidity. Using a range of cut-off values, the association of MCA pulsatility index and umbilicocerebral ratio (UCR) with composite adverse outcome was explored. RESULTS: The study population comprised 856 women. There were two (0.2%) intrauterine deaths. Median gestational age at delivery was 38 (interquartile range (IQR), 37-39) weeks and birth weight was 2478 (IQR, 2140-2790) g. Compared with infants with normal outcome, those with composite adverse outcome (n = 93; 11%) were delivered at an earlier gestational age (36 vs 38 weeks) and had a lower birth weight (1900 vs 2540 g). The first Doppler observation of MCA pulsatility index < 5th percentile and UCR Z-score above gestational-age-specific thresholds (1.5 at 32-33 weeks and 1.0 at 34-36 weeks) had the highest relative risks (RR) for composite adverse outcome (RR 2.2 (95% CI, 1.5-3.2) and RR 2.0 (95% CI, 1.4-3.0), respectively). After adjustment for confounders, the association between UCR Z-score and composite adverse outcome remained significant, although gestational age at delivery and birth-weight Z-score had a stronger association. CONCLUSION: In this prospective multicenter study, signs of cerebral blood flow redistribution were found to be associated with adverse outcome in late preterm singleton pregnancies at risk of fetal growth restriction. Whether cerebral redistribution is a marker describing the severity of fetal growth restriction or an independent risk factor for adverse outcome remains unclear, and whether it is useful for clinical management can be answered only in a randomized trial. © 2020 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of the International Society of Ultrasound in Obstetrics and Gynecology.


Asunto(s)
Desarrollo Fetal , Retardo del Crecimiento Fetal/diagnóstico por imagen , Reología , Ultrasonografía Doppler , Ultrasonografía Prenatal , Adulto , Peso al Nacer , Europa (Continente) , Femenino , Retardo del Crecimiento Fetal/fisiopatología , Peso Fetal , Feto/irrigación sanguínea , Feto/diagnóstico por imagen , Feto/fisiopatología , Edad Gestacional , Humanos , Recién Nacido , Recién Nacido Pequeño para la Edad Gestacional , Nacimiento Vivo , Arteria Cerebral Media/diagnóstico por imagen , Arteria Cerebral Media/embriología , Embarazo , Estudios Prospectivos , Flujo Pulsátil , Valores de Referencia , Mortinato , Arterias Umbilicales/diagnóstico por imagen , Arterias Umbilicales/embriología , Circunferencia de la Cintura
3.
Phys Rev Lett ; 122(16): 165701, 2019 Apr 26.
Artículo en Inglés | MEDLINE | ID: mdl-31075017

RESUMEN

Positron annihilation lifetime spectroscopy is used to experimentally demonstrate the direct relationship between vacancies and the shift of the martensitic transformation temperature in a Ni_{55}Fe_{17}Ga_{28} alloy. The evolution of vacancies assisting the ordering enables shifts of the martensitic transformation up to 50 K. Our results confirm the role that both vacancy concentration and different vacancy dynamics play in samples quenched from the L2_{1} and B2 phases, which dictate the martensitic transformation temperature and its subsequent evolution. Finally, by electron-positron density functional calculations V_{Ni} is identified as the most probable vacancy present in Ni_{55}Fe_{17}Ga_{28}. This work evidences the capability of vacancies for the fine-tuning of the martensitic transformation temperature, paving the way for defect engineering of multifunctional properties.

4.
Biomed Res Int ; 2018: 8961805, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-30105260

RESUMEN

BACKGROUND: Recurrent shoulder dislocations occur much more frequently in adolescents than in the older population but a clear explanation of this incidence does not exist. The aim of the present study was to define the age-related distribution of the elastic fibers (EFs) in the shoulder capsule's extracellular matrix as a factor influencing shoulder instability. MATERIALS AND METHODS: Biopsy specimens were obtained from the shoulder capsule of patients divided preoperatively into three groups: Group 1 consisted of 10 male patients undergoing surgery for unidirectional traumatic anterior instability (TUBS); Group 2 consisted of 10 male patients undergoing surgery for multidirectional instability (MDI); Group 3 represents the control, including 10 patients with no history of instability. In addition to the group as a whole, specific subgroups were analyzed separately on the basis of the age of subjects: > 22 or < to 22 years. All the samples were analyzed by histochemical (Weigert's resorcinol fuchsin and Verhoeff's iron hematoxylin), immunohistochemical (monoclonal antielastin antibody), and histomorphometric methods. RESULTS: Both the elastin density and the percentage of area covered by EFs were significantly higher in younger subjects (<22 years old). Furthermore, the elastin density and the percentage of area covered by EFs were significantly higher in specimens of group of patients affected by multidirectional shoulder instability in comparison to the other two groups. CONCLUSION: Data of the present study confirmed the presence of an age-related distribution of EFs in the human shoulder capsule. The greater amount of EFs observed in younger subjects and in unstable shoulders could play an important role in predisposing the joint to first dislocation and recurrence.


Asunto(s)
Tejido Elástico/patología , Inestabilidad de la Articulación/fisiopatología , Luxación del Hombro/fisiopatología , Adolescente , Adulto , Factores de Edad , Artroscopía , Humanos , Masculino , Proyectos Piloto , Recurrencia , Hombro , Articulación del Hombro , Adulto Joven
5.
Med Hypotheses ; 118: 139-141, 2018 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-30037602

RESUMEN

Shoulder dystocia is a rare but severe obstetric complication associated with an increased risk of brachial plexus palsies, fractures of the clavicle and humerus, hypoxic-ischemic encephalopathy and, rarely, neonatal death. Here we describe a fatal case of shoulder dystocia in a term newborn, although labor was uneventful, fetal heart rate tracing was normal until the delivery of the head and the head-to-body delivery interval (HBDI) occurred within 5 min. Full resuscitation was performed for 35 min without success. Hemoglobin concentration evaluated on the umbilical cord still attached to the placenta was within normal range, while neonatal venous hemoglobin concentration blood gases at 9 min of life showed severe metabolic acidosis and anemia. As previously described by others, our case supports the hypothesis of a hypovolemic shock as the cause of neonatal death, probably due to acute placental retention of fetal blood. The death of the newborn following shoulder dystocia is an event that still presents numerous gaps in knowledge. Further research should focus on.


Asunto(s)
Plexo Braquial/fisiopatología , Distocia/fisiopatología , Choque/fisiopatología , Hombro/fisiopatología , Análisis de los Gases de la Sangre , Resultado Fatal , Femenino , Sangre Fetal , Fracturas Óseas/fisiopatología , Frecuencia Cardíaca Fetal , Humanos , Recién Nacido , Placenta/patología , Embarazo , Resucitación , Factores de Riesgo , Cordón Umbilical/patología , Adulto Joven
6.
Sci Rep ; 7(1): 13328, 2017 10 17.
Artículo en Inglés | MEDLINE | ID: mdl-29042659

RESUMEN

Metamagnetic shape memory alloys have aroused considerable attraction as potential magnetic refrigerants due to the large inverse magnetocaloric effect associated to the magnetic-field-induction of a reverse martensitic transformation (martensite to austenite). In some of these alloys, the austenite phase can be retained on cooling under high magnetic fields, being the retained phase metastable after field removing. Here, we report a giant direct magnetocaloric effect linked to the anomalous forward martensitic transformation (austenite to martensite) that the retained austenite undergoes on heating. Under moderate fields of 10 kOe, an estimated adiabatic temperature change of 9 K has been obtained, which is (in absolute value) almost twice that obtained in the conventional transformation under higher applied fields. The observation of a different sign on the temperature change associated to the same austenite to martensite transformation depending on whether it occurs on heating (retained) or on cooling is attributed to the predominance of the magnetic or the vibrational entropy terms, respectively.

7.
Musculoskelet Surg ; 98 Suppl 1: 35-9, 2014 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-24659194

RESUMEN

BACKGROUND: Late sequelae of septic arthritis of the glenohumeral joint are very rare and represent a potentially devastating condition that can result in irreversible changes at the level of joint and surrounding soft tissues. MATERIALS AND METHODS: Between January 2001 and December 2010, ten patients were treated at our institution for late sequelae of septic arthritis of the shoulder. There were eight men and two women with a mean age of 67.9 years (range 62-74 years). Eight of ten patients had previously received three or more intra-articular or subacromial injections. Surgical treatment consisted of open joint debridement, humeral head resection and implantation of an antibiotic spacer followed by a 6-8-week course of intravenous antibiotics. RESULTS: White blood cell count, C-reactive protein and erythrocyte sedimentation rate normalized between 6 and 8 weeks postoperatively in all patients. No recurrent infection was observed in any patient. Postoperatively, the mean Constant score was 37 (range 28-46) and mean DASH score was 54 (range 40-69), demonstrating a very limited function in these patients. There was a trend toward improved outcome scores in patients who underwent early surgical debridement. Five patients underwent delayed reconstruction with a reverse shoulder prosthesis, and at minimum 1-year follow-up, the mean Constant score was 56 (range 47-69) and mean DASH score was 33 (31-38). CONCLUSIONS: Antibiotic spacers are able to deliver antibiotics locally to the infected tissue while reducing the dead space and stabilizing the glenohumeral joint. An early, aggressive management of the infection is essential to maximize clinical outcomes and avoid either significant destruction or ankylosis of the shoulder joint.


Asunto(s)
Antibacterianos/administración & dosificación , Artritis Infecciosa/diagnóstico por imagen , Artritis Infecciosa/terapia , Desbridamiento , Imagen por Resonancia Magnética , Anciano , Artritis Infecciosa/microbiología , Desbridamiento/métodos , Femenino , Estudios de Seguimiento , Humanos , Inyecciones Intralesiones , Masculino , Persona de Mediana Edad , Rango del Movimiento Articular , Reoperación , Estudios Retrospectivos , Articulación del Hombro/cirugía , Resultado del Tratamiento
8.
J Phys Condens Matter ; 25(48): 484005, 2013 Dec 04.
Artículo en Inglés | MEDLINE | ID: mdl-24201042

RESUMEN

The martensitic transformation (MT) of metamagnetic shape memory alloys is very sensitive to the applied magnetic field and atomic order. We analyze the alloy Ni50Mn34.5In15.5 in magnetic fields up to 13 T. The alloy has been prepared both in an ordered state by slow cooling, and in a disordered state by rapid quenching. In both cases the dependence of the martensitic transition temperature on the field is highly nonlinear. Such departure from linearity is due to a decrease of the entropy change at the transition, ΔS, with the applied field. This can be explained by the ordering effect of the magnetic field on the frustrated magnetic structure of the alloy in the martensitic phase. Compliance with a recent model, relying on the strong magnetoelastic interactions in these compounds, is very satisfactory.

9.
Musculoskelet Surg ; 97 Suppl 1: 39-47, 2013 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-23605080

RESUMEN

BACKGROUND: We evaluated the role of matrix metalloproteases (MMPs) and their inhibitors which are involved in extracellular matrix remodeling and degradation, in the pathogenesis of chronic rotator cuff tears. MATERIALS AND METHODS: Tendon samples were harvested from 13 patients who underwent arthroscopic repair of a rotator cuff tear. Supraspinatus biopsy specimens were harvested en bloc from the arthroscopically intact middle portion of the tendon more than 1 cm from the torn edge, from the lateral edge of the tear, and from the superior one third of the macroscopically intact subscapularis tendon used as control. Histological analysis and an evaluation of the activity of specific metalloproteases and the tissue inhibitors of metalloprotease (TIMP-1, TIMP-2) was done blindly by multiplex sandwich ELISA (Search-Light technology) in each specimen RESULTS: Histological evidence of tendinopathy was present in all patients with a tear of the rotator cuff, and not in the macroscopically intact subscapularis tendon. There was a significant increase in MMP 1, MMP 2, MMP 3 and in TIMP-1, TIMP-2 levels in all specimens examined, including the macroscopically intact portion of the supraspinatus tendon and in the control specimens CONCLUSIONS: The tissue in the ruptured area of the supraspinatus tendon undergoes marked rearrangement at molecular levels. This involves the activity of MMP 1, 2 and 3, and supports the critical role of MMPs in the tendon physiology. Seemingly intact parts of the injured supraspinatus tendon can present tendinopathic features, with altered cellular metabolism.


Asunto(s)
Metaloproteasas/metabolismo , Lesiones del Manguito de los Rotadores , Manguito de los Rotadores/enzimología , Inhibidor Tisular de Metaloproteinasa-1/metabolismo , Inhibidor Tisular de Metaloproteinasa-2/metabolismo , Adulto , Anciano , Femenino , Humanos , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Manguito de los Rotadores/anatomía & histología , Manguito de los Rotadores/patología
10.
Minerva Ginecol ; 63(4): 387-98, 2011 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-21747347

RESUMEN

Early evidence suggests that in-utero stem cell transplantation represents a new therapeutic strategy for different congenital disease. Moreover, gene therapy constitutes one of the most promising new approach to treat a wide spectrum of genetic disorders. It was shown that the fetus could represent an ideal recipient because of his immunologic early naiveté in gestation that reduces the risk of immunoreactions. Clinical experience in human fetus was performed in order to treat immunodeficiency and metabolic disorders, hemoglobinopathies and some other genetic diseases. Use of alternative source (i.e., cord blood, placenta, membrane, amniotic fluid, fetal tissue) of stem cell transplanted has been only one of the several strategies to improve donor cell advantages on host stem cell. The present review focused on the clinical use and therapeutic potential of in-utero stem cell transplantation, reporting the outcome of human cases treated and the limits of this therapy and possible future applications.


Asunto(s)
Enfermedades Fetales/cirugía , Feto/cirugía , Trasplante de Células Madre/métodos , Células Madre Adultas/trasplante , Células Madre Embrionarias/trasplante , Femenino , Terapia Genética , Trasplante de Células Madre Hematopoyéticas , Humanos , Trasplante de Células Madre Mesenquimatosas , Embarazo
11.
J Microsc ; 237(3): 374-8, 2010 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-20500399

RESUMEN

Elemental powders of Co, Ni and Al in the proper amounts to obtain Co(35)Ni(40)Al(25) and Co(40)Ni(35)Al(25) nominal compositions were ball milled in a high-energy mill for 80 h. After 40 h of milling, the formation of a Co (Ni, Al) solid solution with f.c.c. structure was verified by a change of the original lattice parameter and crystallite size. Analytical transmission electron microscopy observations and X-ray diffraction measurements of the final Co (Ni, Al) solid solution showed that the crystallite size scattered from 4 to 8 nm and lattice parameter a = 0.36086 nm. The chemical EDS point analysis of the milled powder particles allowed the calculation of the e/a ratio and revealed a high degree of chemical homogeneity of the powders. Hot pressing in vacuum of the milled powders resulted in obtaining compacts with a density of about 70% of the theoretical one. An additional heat treatment increased the density and induced the martensitic transformation in a parent phase. Selected area diffraction patterns and dark field images obtained from the heat-treated sample revealed small grains around 300 nm in diameter consisting mainly of the ordered gamma phase (gamma'), often appearing as twins, and a small amount of the L1(0) ordered martensite.

12.
J Phys Condens Matter ; 22(41): 416001, 2010 Oct 20.
Artículo en Inglés | MEDLINE | ID: mdl-21386603

RESUMEN

Ferromagnetic shape memory alloys undergo a martensitic transformation accompanied by a change in the magnetic and vibrational properties. However, these property changes are not independent. In this paper, the interplay between magnetic and vibrational properties in the martensitic transformation entropy change has been analyzed for Ni-Fe-Ga ferromagnetic shape memory alloys. The martensitic transformation entropy change has a magnetic and a vibrational contribution, ΔS(p−>m)=ΔS(vib)(p−>m) + ΔS(mag)(p−>m). Using a mean field approximation for the magnetic entropy, the full entropy ΔS(p−>m) has been decomposed and the magnetic contribution ΔS(mag)(p−>m) calculated. Upon removing the magnetic term, the vibrational entropy ΔS(vib)(p−>m) does not change substantially in the composition range where T(M) is below T(C). This latter contribution to the martensitic transformation entropy change has been analyzed using a Debye distribution for the density of states and a proportion of Einstein modes that account for the anomalous phonon mode of the austenite.

13.
J Microsc ; 236(2): 143-8, 2009 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-19903241

RESUMEN

Two powder alloys from the beta phase region of compositions Co(28.5)Ni(36.5)Al(35) and Co(35)Ni(30)Al(35) were ball milled for 80 h in a high energy ball mill. The formation of amorphous structure was observed after 40 h of milling and further milling did not change their structure. The analytical and high-resolution transmission electron microscopy (TEM, HREM) examination of powder structure showed that nanoparticles of L1(0) phase of size of about 5 nm were present within the amorphous matrix. The vacuum hot pressing of the milled powders under pressure of 400 MPa at 700 degrees C for 12 min resulted in the formation of compacts with density of about 70% of the theoretical one. The additional heat treatment at 1300 degrees C for 6 h followed by water quenching, led to significant improvement of density and induced the martensitic transformation manifested by a broad heat effect. The characteristic temperatures of the transformation were determined using DSC measurements, which revealed only small differences within the examined alloys compositions. TEM structure studies of heat-treated alloys allowed to identify the structure of an ordered beta (B2) phase and L1(0) martrensite.

14.
Cell Prolif ; 41 Suppl 1: 41-50, 2008 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-18181944

RESUMEN

This study aims to investigate engraftment of human cord blood and foetal bone marrow stem cells after in utero transplantation via the intracoelomic route in the sheep. Here, we performed transplantation in 14 single and 1 twin sheep foetuses at 40-47 days of development, using a novel schedule for injection. (i) Single injection of CD34(+) human cord blood stem cells via the coelomic route (from 10 to 50 x 10(4)) in seven single foetuses. (ii) Single injection of CD34(+) foetal bone marrow stem cells via the intracoelomic route with further numbers of cells (20 x 10(5) and 8 x 10(5), respectively) in three single and in one twin foetuses. (iii) Double fractioned injection (20-30 x 10(6)) via the coelomic route and 20 x 10(6) postnatally, intravenously, shortly after birth of CD3-depleted cord blood stem cells in four single foetuses. In the first group, three single foetuses showed human/sheep chimaerism at 1, 8 and 14 months after birth. In the second group, the twin foetuses showed human/sheep chimaerism at 1 month after birth. In the third group, only two out of four single foetuses that underwent transplantation showed chimaerism at 1 month. While foetal bone marrow stem cells showed good short-term engraftment (1 month after birth), cord blood stem cells were able to persist longer in the ovine recipients (at 1, 8 and 14 months after birth).


Asunto(s)
Trasplante de Médula Ósea , Trasplante de Células Madre de Sangre del Cordón Umbilical , Feto/citología , Animales , Antígenos CD34/metabolismo , Complejo CD3/metabolismo , Quimerismo , Humanos , Ovinos , Factores de Tiempo , Quimera por Trasplante
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